No.My aging Denon is I believe specced for 6-8ohm speakers. I was thinking of upgrading my fronts, starting with the center for now, with the Monoprice Monolith THX-365 series. This is for a 7.1 setup with 18" DIY sub. I don't think this Denon model supports Atmos but that is in the cards next year maybe.
Would the 4 ohm center, and ultimately 4 ohm L-R, be expected to cause problems with my AVR? I tend to start movies at -12 to see how loud they are and then end up anywhere between there and 0.
The trend for many manufacturers is a 4-ohm load in an attempt to keep up with the Joneses in sensitivity. So, 4 ohms is not unusual.